From patchwork Thu Feb 16 16:08:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Huewe X-Patchwork-Id: 9577659 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2C0446049F for ; Thu, 16 Feb 2017 16:09:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1EB352860B for ; Thu, 16 Feb 2017 16:09:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 138C828630; Thu, 16 Feb 2017 16:09:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9C21C28627 for ; Thu, 16 Feb 2017 16:09:30 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-2.v29.ch3.sourceforge.com) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ceOcb-00019O-Re; Thu, 16 Feb 2017 16:09:29 +0000 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ceOca-000192-QD for tpmdd-devel@lists.sourceforge.net; Thu, 16 Feb 2017 16:09:28 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of infineon.com designates 217.10.52.18 as permitted sender) client-ip=217.10.52.18; envelope-from=peter.huewe@infineon.com; helo=smtp2.infineon.com; Received: from smtp2.infineon.com ([217.10.52.18]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1ceOcZ-0004Ez-Qo for tpmdd-devel@lists.sourceforge.net; Thu, 16 Feb 2017 16:09:28 +0000 X-SBRS: None Received: from unknown (HELO mucxv003.muc.infineon.com) ([172.23.11.20]) by smtp2.infineon.com with ESMTP/TLS/AES256-GCM-SHA384; 16 Feb 2017 17:08:50 +0100 Received: from MUCSE604.infineon.com (unknown [172.23.7.105]) by mucxv003.muc.infineon.com (Postfix) with ESMTPS; Thu, 16 Feb 2017 17:08:49 +0100 (CET) Received: from MUCSE612.infineon.com (172.23.7.113) by MUCSE604.infineon.com (172.23.7.105) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Thu, 16 Feb 2017 17:08:49 +0100 Received: from osboxes.agb.infineon.com (172.29.170.145) by MUCSE612.infineon.com (172.23.7.113) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Thu, 16 Feb 2017 17:08:48 +0100 From: Peter Huewe To: Jarkko Sakkinen Date: Thu, 16 Feb 2017 16:08:24 +0000 Message-ID: <1487261306-2494-4-git-send-email-peter.huewe@infineon.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487261306-2494-1-git-send-email-peter.huewe@infineon.com> References: <1487261306-2494-1-git-send-email-peter.huewe@infineon.com> MIME-Version: 1.0 X-Originating-IP: [172.29.170.145] X-ClientProxiedBy: MUCSE601.infineon.com (172.23.7.102) To MUCSE612.infineon.com (172.23.7.113) X-Headers-End: 1ceOcZ-0004Ez-Qo Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, Christophe Ricard , Peter Huewe , Alexander@mail.wl.linuxfoundation.org Subject: [tpmdd-devel] [PATCH 3/5] tpm_tis_spi: Check correct byte for wait state indicator X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces@lists.sourceforge.net X-Virus-Scanned: ClamAV using ClamSMTP Wait states are signaled in the last byte received from the TPM in response to the header, not the first byte. Check rx_buf[3] instead of rx_buf[0]. Cc: Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") Signed-off-by: Alexander Steffen Signed-off-by: Peter Huewe Reviewed-by: Jarkko Sakkien --- drivers/char/tpm/tpm_tis_spi.c | 40 +++++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 19 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index d782b9974c14..16938e2253d2 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -60,7 +60,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u8 len, u8 *buffer, u8 direction) { struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data); - int ret, i; + int ret; struct spi_message m; struct spi_transfer spi_xfer = { .tx_buf = phy->tx_buf, @@ -85,25 +85,27 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u8 len, if (ret < 0) goto exit; - phy->tx_buf[0] = 0; - - /* According to TCG PTP specification, if there is no TPM present at - * all, then the design has a weak pull-up on MISO. If a TPM is not - * present, a pull-up on MISO means that the SB controller sees a 1, - * and will latch in 0xFF on the read. - */ - for (i = 0; (phy->rx_buf[0] & 0x01) == 0 && i < TPM_RETRY; i++) { - spi_xfer.len = 1; - spi_message_init(&m); - spi_message_add_tail(&spi_xfer, &m); - ret = spi_sync_locked(phy->spi_device, &m); - if (ret < 0) + if ((phy->rx_buf[3] & 0x01) == 0) { + // handle SPI wait states + int i; + + phy->tx_buf[0] = 0; + + for (i = 0; i < TPM_RETRY; i++) { + spi_xfer.len = 1; + spi_message_init(&m); + spi_message_add_tail(&spi_xfer, &m); + ret = spi_sync_locked(phy->spi_device, &m); + if (ret < 0) + goto exit; + if (phy->rx_buf[0] & 0x01) + break; + } + + if (i == TPM_RETRY) { + ret = -ETIMEDOUT; goto exit; - } - - if (i == TPM_RETRY) { - ret = -ETIMEDOUT; - goto exit; + } } spi_xfer.cs_change = 0;